In forming cartons or packages for such products as frozen foods, most prior containers have been fabricated from a one-piece blank wherein a lid is formed contiguous with the tray blank and, after forming and filling the tray, the lid is folded over to complete the closure of the package. Because of various advantages, there is now being used a package comprising a tray and a separately formed lid with the two components being fixed together after the tray is filled.
Of various advantages derived from the two piece carton the primary advantage involves the easier handling of the tray. Naturally if a lid is fixed to the tray, it must be conveyed therewith in the open position during the filling operation thereby greatly complicating the handling and filling of the container. In addition, with many products the nomenclature or identification of the product can be printed directly on the lid requiring the lid to be made of better paper stock. With the two-piece construction, the tray can be made of a lower grade stock which is less expensive. Also with printing on the lid, the lid only need be changed as the product for filling the tray is changed to change the identification of the carton contents.
However, after filling the tray of the two-piece carton, the lid must be brought into the proper position and fixed to the tray to complete the sealing of the container. If the forming apparatus can be made to operate at faster and more efficient speeds, the packaging process is made more economical. This result is derived from the fact that fewer packaging apparatus need be provided, thereby cutting down not only on the capital investment but on the floor space necessary to complete this operation. It is further known that in such mechanical apparatus, the more fluid or continuous the process, the less wear on both the apparatus and the package being handled. Thus it is the primary object of the subject invention to provide an apparatus for joining and sealing the tray and lid of a two-piece carton by bringing together and joining the separate components in one continuous process.